Current methods and devices to splice or terminate composite core reinforced cables, such as those disclosed in PCT Application No. PCT/US03/12520 and incorporated by reference herein, do not exist. Generally, the splice functions as both a mechanical and an electrical junction between the ends of two cables. Splices for use with traditional aluminum conductor steel reinforced cable are known in the art. However, due to the differences in the physical properties of aluminum conductor composite core reinforced cables, as compared to traditional aluminum conductor steel reinforced cable, existing devices and methods to splice will not be effective.
Traditional aluminum conductor steel reinforced cable (ACSR) is formed from a set of twisted aluminum conductors wrapped around a core of steel wires. In ACSR type cables, the steel reinforces the tensile strength of the aluminum. For example, in a properly sagged conductor at normal operating temperatures in the range of 60° C. to 75° C. the aluminum stranding of ACSR conductor carries approximately 40% of the tensile load. The balance is carried by the steel. As the conductor increases in temperature, the aluminum, expanding at a faster rate than the steel, transfers more load to the steel. Connectors designed for use with ACSR are designed with this in mind, where the steel component of the system does not carry the full tension of the conductor. Therefore, the steel components of these connectors are sized accordingly.
To splice two ACSR cable spans, linemen use a device such as a full tension compression splice. For this device, a lineman strips the aluminum away from the steel core. A sleeve or die is placed over the end of the exposed core. The lineman leaves a small part of the steel core exposed beyond the end of the sleeve. A compression vise is used to affix the sleeve to the steel core. The sleeve and steel core from both cables are then inserted into a second tube. The tube is long enough to cover the sleeve and part of the aluminum conductor that was not stripped away. This tube is also crimped with a compression vise. These implements create compression fittings that hold both the aluminum conductor and the steel core.
Splices designed for ACSR cables are ineffective with aluminum conductor composite core reinforced cables. As opposed to ACSR cables, the composite core member is the load carrying member in aluminum conductor composite core reinforced cables and connectors must be designed with this in mind. Accordingly, crimping a tube to the aluminum conductor does not hold together the composite core load-bearing members of the two cables. Moreover, because the composite core is much stronger than a traditional steel core and because the conventional inner steel tubes of a traditional splice are imprecise, crimping of the steel tube to the composite core would not provide adequate grip at the higher rated tensions for example, 41,000 pounds vs. 31,500 for a conventional Drake size. This lack of precision may further cause stress concentration points which may compromise longevity of the core.
Thus, a need exists for an apparatus to splice and terminate composite core reinforced cables and other composite core cables.